| 🠘 | 1. | Plant without true flowers or seeds; reproduction by 1-celled
spores; always herbaceous | 🠚 5. |
| | 1. | Plant with true flowers bearing stamens or carpels or mostly both,
and seeds containing a multicelled embryo (SPERMATOPHYTA) | 🠚 2. |
| | | | |
| 🠘 | 2. | Trees or shrubs with needlelike or scalelike leaves; flowers
mostly unisexual, lacking perianth; ovules naked, not enclosed
in ovary | 🠚 21. |
| | 2. | Trees, herbs, or shrubs with leaves of diverse form, needlelike,
scalelike, or flat; flowers bisexual or unisexual, perianth
usually present; ovules completely enclosed in ovary (ANGIOSPERMAE) | 🠚 3. |
| | | | |
| 🠘 | 3. | Leaves usually parallel-veined, mostly alternate and entire;
parts of flowers usually in threes, not in fives; embryo with
single cotyledon | 🠚 23. |
| | 3. | Leaves net-veined, usually pinnately or palmately so; parts
of flowers mostly in fours or fives; embryo with 2 cotyledons
in most cases. Exceptions NYMPHAEACEAE, some Corydalis, and
some RANUNCULACEAE, with but 1. (DICOTYLEDONEAE) | 🠚 4. |
| | | | |
| 🠘 | 4. | Petals distinct from each other or lacking. Exceptions (petals
somewhat united near base): CRASSULACEAE and FUMARIACEAE, which appear
in key to METACHLAMYDEAE as well. (CHORIPETALAE) | 🠚 36. |
| | 4. | Petals united, at least at base. Exceptions: EMPETRACEAE, which
occurs only in key to {ARCHICHLAMYDEAE}; PYROLACEAE and ERICACEAE, which
occur in both keys, (SYMPETALAE) | 🠚 83. |
| | | | |
| 🠘 | 5. | Stems of hollow joints; leaves whorled and forming
sheath at nodes: EQUISETACEAE | |
| | 5. | Stems not jointed; leaves not fused into sheath | 🠚 6. |
| | | | |
| 🠘 | 6. | Leaves not differentiated into lamina and petiole | 🠚 7. |
| | 6. | Leaves with distinct lamina and petiole | 🠚 9. |
| | | | |
| 🠘 | 7. | Leaves forming basal rosette; sporangia at base of rosette
leaves: ISOETACEAE | |
| | 7. | Leaves not forming basal rosette; sporangia in terminal cones | 🠚 8. |
| | | | |
| 🠘 | 8. | Sterile leaves 6-8 mm long, without ligule; spores of 1 kind,
small: LYCOPODIACEAE | |
| | 8. | Sterile leaves less than 5 mm long, with minute, transverse
ligule near base; spores of 2 kinds, minute (male) and large (female,
fewer): SELAGINELLACEAE | |
| | | | |
| 🠘 | 9. | Leaf single; sporangia in stalked spike or panicle from base of
green blade, large, globular, without annulus: OPHIOGLOSSACEAE | |
| | 9. | Leaves more than 1; sporangia borne on underside of leaf, small-stalked, with annulus of thick-walled cells on side | 🠚 10. |
| | | | |
| 🠘 | 10. | Fertile and sterile leaves dissimilar | 🠚 11. |
| | 10. | Fertile and sterile leaves similar | 🠚 13. |
| | | | |
| 🠘 | 11. | Leaves 2—4-pinnate: CRYPTOGRAMMACEAE | |
| | 11. | Leaves 1-pinnate | 🠚 12. |
| | | | |
| 🠘 | 12. | Pinnae pinnatifid: ATHYRIACEAE (Matteuccia) | |
| | 12. | Pinnae entire: BLECHNACEAE | |
| | | | |
| 🠘 | 13. | Leaves mostly not more than one cell thick: HYMENOPHYLLACEAE | |
| | 13. | Leaves more than one cell thick | 🠚 14. |
| | | | |
| 🠘 | 14. | Leaves pinnatifid, 1-pinnate or dichotomously forked 1-3 times | 🠚 15. |
| | 14. | Leaves pinnately divided | 🠚 16. |
| | | | |
| 🠘 | 15. | Leaves 1-pinnate or dichotomously forked: ASPLENIACEAE | |
| | 15. | Leaves pinnatifid: POLYPODIACEAE | |
| | | | |
| 🠘 | 16. | Sori covered by deflexed margin of leaf | 🠚 17. |
| | 16. | Sori not covered by deflexed margin of leaf | 🠚 18. |
| | | | |
| 🠘 | 17. | Rhizome short; frond membranaceous, palmately forking: ADIANTHACEAE | |
| | 17. | Rhizome coarse, extensively creeping; frond coarse, coriaceous,
tripinnate: HYPOLEPIDACEAE | |
| | | | |
| 🠘 | 18. | Sori sobmarginal: THELYPTERIDACEAE | |
| | 18. | Sori along veins | 🠚 19. |
| | | | |
| 🠘 | 19. | Indusium wanting or nearly obsolete: ATHYRIACEAE (Athyrium) | |
| | 19. | Indusium present, at least in young fronds | 🠚 20. |
| | | | |
| 🠘 | 20. | Indusium borne beneath sorus, surrounding sorus in cuplike structure: ATHYRIACEAE | |
| | 20. | Indusium spreading from above or from 1 side, over sorus: ASPIDIACEAE | |
| | | | |
| 🠘 | 21. | Female flowers solitary; seed single, bony, surrounded by fleshy cup (aril): TAXACEAE | |
| | 21. | Female flowers in cones (in Juniperus, berrylike); seeds without fleshy cup | 🠚 22. |
| | | | |
| 🠘 | 22. | Leaves alternate or 2-5 together on short shoots or spurs: PINACEAE | |
| | 22. | Leaves opposite or whorled: CUPRESSACEAE | |
| | | | |
| 🠘 | 23. | Plant minute, 1-10 mm long, free-floating,
consisting of membranaceous stem or frond without obvious
differentiation into stems and leaves | |
| | 23. | Plant terrestrial or aquatic, rooted in mud; plant
larger, with stem and (sometimes scale- like) leaves | 🠚 24. |
| | | | |
| 🠘 | 24. | Inflorescence a simple, fleshy spike (spadix) with small flowers,
subtended by large bract (spathe); leaves broad, in dense rosettes: ARACEAE | |
| | 24. | Inflorescence not a spadix; leaves grasslike or broad | 🠚 25. |
| | | | |
| 🠘 | 25. | Perianth lacking or reduced, not petal-like in color and texture,
consisting of bristles or mere scales | 🠚 26. |
| | 25. | Perianth well developed, with at least the inner segments petaloid in color and texture | 🠚 33. |
| | | | |
| 🠘 | 26. | Flowers in axils of regularly imbricated scales and concealed by
scales | 🠚 27. |
| | 26. | Flowers in axils of bracts or, if subtended by bracts, exceeding
or equaling them, not concealed | 🠚 28. |
| | | | |
| 🠘 | 27. | Leaf sheaths split lengthwise; stem mostly hollow and terete;
leaves usually 2-ranked: GRAMINEAE | |
| | 27. | Leaf sheaths forming closed tube around stem (sometimes rupturing in age);
stem often triangular in cross section; leaves usually 3-ranked: CYPERACEAE | |
| | | | |
| 🠘 | 28. | Flowers unisexual, in heads or dense spikes | 🠚 29. |
| | 28. | Flowers perfect | 🠚 30. |
| | | | |
| 🠘 | 29. | Flowers in densely crowded terminal spikes, the lower half thick,
dark brown, pistillate, the upper thinner, staminate: TYPHACEAE | |
| | 29. | Flowers in globose heads, the lower pistillate, the upper
staminate: SPARGANIACEAE | |
| | | | |
| 🠘 | 30. | Plant floating or submerged: POTAMOGETONACEAE | |
| | 30. | Plant terrestrial | 🠚 31. |
| | | | |
| 🠘 | 31. | Carpels free (except at base); leaves with conspicuous pore at
apex: SCHEUCHZERIACEAE | |
| | 31. | Carpels more or less completely united, separating at maturity; leaves
without conspicuous pore at apex | 🠚 32. |
| | | | |
| 🠘 | 32. | Flowers in unbranched racemes; styles short or lacking
JUNCAGINACEAE | |
| | 32. | Flowers in cymes or branched inflorescences; styles 3, distinct
JUNCACEAE | |
| | | | |
| 🠘 | 33. | Ovary wholly inferior | 🠚 34. |
| | 33. | Ovary superior | 🠚 35. |
| | | | |
| 🠘 | 34. | Flowers regular; ovary with 3 rooms; stamens 3: IRIDACEAE | |
| | 34. | Flowers irregular; 1 petal forming a lip with a spur; ovary
1-roomed; stamens 1, in Cypripedium 2: ORCHIDACEAE | |
| | | | |
| 🠘 | 35. | Outer 3 perianth segments sepal-like, the inner 3 petal-like
ALISMACEAE | |
| | 35. | Sepals of same coloraspetals: LILIACEAE | |
| | | | |
| 🠘 | 36. | Plant parasitic on branches of western hemlock, lacking chlorophyll (witch’s broom): LORANTHACEAE | |
| | 36. | Plant rooting in ground | 🠚 37. |
| | | | |
| 🠘 | 37. | Petals lacking or not evident (calyx sometimes petaloid, as in
RANUNCULACEAE, Polygonum, and Eriogonum) | 🠚 38. |
| | 37. | Petals present, evident; calyx also present (caducous at anthesis
in PAPAVERACEAE) | 🠚 53. |
| | | | |
| 🠘 | 38. | Plant definitely woody, with woody branches; tree or shrub | 🠚 39. |
| | 38. | Plant herbaceous (sometimes slightly woody at base) | 🠚 43. |
| | | | |
| 🠘 | 39. | Flowers in catkins; plant not covered with stellate hairs | 🠚 40. |
| | 39. | Flowers not in catkins | 🠚 42. |
| | | | |
| 🠘 | 40. | Fruit a many-seeded capsule; seeds with tuft of long hair;
stamens with long filaments: SALICACEAE | |
| | 40. | Fruit a 1-seeded nutlet; seeds without tuft of hair | 🠚 41. |
| | | | |
| 🠘 | 41. | Female flowers solitary, in axils of bracts; male flowers in
small, lateral catkins; leaves dotted with resin glands: MYRICACEAE | |
| | 41. | Female flowers in erect, cylindrical or ovoid catkins, 2-3 in
axils of bracts; male flowers in drooping catkins: BETULACEAE | |
| | | | |
| 🠘 | 42. | Stamens 4 or 8; plant covered with stellate hairs or scales;
leaves broad, deciduous: ELAEAGNACEAE | |
| | 42. | Stamens 3; plant not covered with stellate hairs; leaves linear,
needlelike, evergreen: EMPETRACEAE | |
| | | | |
| 🠘 | 43. | Plant aquatic, submerged or, as water recedes or evaporates, in
wet mud | 🠚 44. |
| | 43. | Plant terrestrial (sometimes growing in wet places) | 🠚 47. |
| | | | |
| 🠘 | 44. | Calyx petaloid, colored: RANUNCULACEAE | |
| | 44. | Calyx not petaloid | 🠚 45. |
| | | | |
| 🠘 | 45. | Leaves opposite, entire, often crowded in terminal rosettes
CALLITRICHACEAE | |
| | 45. | Leaves whorled, entire or dissected | 🠚 46. |
| | | | |
| 🠘 | 46. | Leaves dichotomously 2 or 3 times forked; ovary superior
CERATOPHYLLACEAE | |
| | 46. | Leaves entire or pinnatifid: HALORAGACEAE | |
| | | | |
| 🠘 | 47. | Ovary more or less inferior; calyx adnate to floral tube; leaves entire, cblong, glabrous (root parasites): SANTALACEAE | |
| | 47. | Ovary superior, free from calyx (although sometimes surrounded by it) | 🠚 48. |
| | | | |
| 🠘 | 48. | Pistils several; stamens more than 10; calyx petaloid, conspicuous
RANUNCULACEAE | |
| | 48. | Pistil 1; calyx green or petaloid | 🠚 49. |
| | | | |
| 🠘 | 49. | Style and stigma single; flowers in axillary clusters; stamens 4
: URTICACEAE | |
| | 49. | Styles and stigmas more than 1 | 🠚 50. |
| | | | |
| 🠘 | 50. | Flowers enclosed in campanulate involucrum; calyx bright yellow
POLYGONACEAE (Eriogonum) | |
| | 50. | Flowers without involucrum; calyx sometimes petaloid, not bright
yellow | 🠚 51. |
| | | | |
| 🠘 | 51. | Stipules united into sheath above each node; calyx more or less
petaloid: POLYGONACEAE | |
| | 51. | Stipules not united into sheath; calyx not petaloid | 🠚 52. |
| | | | |
| 🠘 | 52. | Bracts not scarious; plant mostly mealy, scurfy, or fleshy:
CHENOPODIACEAE | |
| | 52. | Bracts subtending flowers, scarious; plant not mealy, scurfy, or
fleshy: AMARANTHACEAE | |
| | | | |
| 🠘 | 53. | Stamens numerous, more than twice as many as petals | 🠚 54. |
| | 53. | Stamens not more than twice as many as petals | 🠚 58. |
| | | | |
| 🠘 | 54. | Plants aquatic, with broad, cordate, floating leaves: NYMPHAEACEAE | |
| | 54. | Plants terrestrial, leaves various | 🠚 55. |
| | | | |
| 🠘 | 55. | Sepals 2, caducous at anthesis | 🠚 56. |
| | 55. | Sepals more than 2 | 🠚 57. |
| | | | |
| 🠘 | 56. | Flowers regular: PAPAVERACEAE | |
| | 56. | Flowers irregular: FUMARIACEAE | |
| | | | |
| 🠘 | 57. | Stamens inserted in receptacle, free from calyx: RANUNCULACEAE | |
| | 57. | Stamens borne on calyx or on rim of hypanthium: ROSACEAE | |
| | | | |
| 🠘 | 58. | Stamens inserted into margin of woolly disk lining base of calyx:
ROSACEAE (Sibbaldia) | |
| | 58. | Stamens not thus inserted | 🠚 59. |
| | | | |
| 🠘 | 59. | Pistils more than 1, nearly or quite separate | 🠚 60. |
| | 59. | Pistil 1 (consisting of 1 or more, more or less united carpels) | 🠚 61. |
| | | | |
| 🠘 | 60. | Plant succulent; carpels with same number as calyx segments: CRASSULACEAE | |
| | 60. | Plant not succulent; carpels fewer than calyx segments, mostly 2:
SAXIFRAGACEAE | |
| | | | |
| 🠘 | 61. | Styles 2-5, separate near base | 🠚 62. |
| | 61. | Style 1 (sometimes more or less divided toward apex) | 🠚 71. |
| | | | |
| 🠘 | 62. | Plant woody; shrub or small tree | 🠚 63. |
| | 62. | Plant herbaceous | 🠚 64. |
| | | | |
| 🠘 | 63. | Ovary inferior; fruit a berry; leaves palmately lobed:
SAXIFRAGACEAE (Ribes) | |
| | 63. | Ovary superior; fruit winged: ACERACEAE | |
| | | | |
| 🠘 | 64. | Plant submerged, aquatic; leaves finely dissected: HALORAGACEAE
(Muyriophyllum) | |
| | 64. | Plant terrestrial | 🠚 65. |
| | | | |
| 🠘 | 65. | Ovary more or less inferior | 🠚 66. |
| | 65. | Ovary superior | 🠚 68. |
| | | | |
| 🠘 | 66. | Seeds many in each room of ovary; flowers not in umbels: SAXIFRAGACEAE | |
| | 66. | Seeds solitary in each room of ovary; flowers in umbels | 🠚 67. |
| | | | |
| 🠘 | 67. | Fruit a berry; densely prickly, decumbent shrub: ARALIACEAE | |
| | 67. | Fruit a schizocarp, splitting at maturity into 2 mericarps; herb:
UMBELLIFERAE | |
| | | | |
| 🠘 | 68. | Leaves reddish, with numerous stout glands on upper surface;
insectivorous: DROSERACEAE | |
| | 68. | Leaves green, lacking stout glands; not insectivorous | 🠚 69. |
| | | | |
| 🠘 | 69. | Sepals 2; plant more or less fleshy: PORTULACACEAE | |
| | 69. | Sepals more than 2, free or united into tube | 🠚 70. |
| | | | |
| 🠘 | 70. | Ovary 1-celled; stamens twice as many as petals: CARYOPHYLLACEAE | |
| | 70. | Ovary 5-celled; fertile stamens as many as petals: LINACEAE | |
| | | | |
| 🠘 | 71. | Ovary inferior | 🠚 72. |
| | 71. | Ovary superior | 🠚 74. |
| | | | |
| 🠘 | 72. | Shrub; flowers in lateral racemes or solitary; leaves alternate; stamens
mostly 5: SAXIFRAGACEAE (Ribes) | |
| | 72. | Herb; stamens 2, 4, or 8 | 🠚 73. |
| | | | |
| 🠘 | 73. | Flowers axillary or in terminal racemes; stamens 2 or 8: ONAGRACEAE | |
| | 73. | Flowers in umbelliform cyme, surrounded by mostly 4 large, white,
petaloid bracts; stamens 4: CORNACEAE | |
| | | | |
| 🠘 | 74. | Plant a low shrub: ERICACEAE (Ledum) | |
| | 74. | Plant herbaceous | 🠚 75. |
| | | | |
| 🠘 | 75. | Sepals 2 | 🠚 76. |
| | 75. | Sepals more than 2 | 🠚 78. |
| | | | |
| 🠘 | 76. | Plant more or less fleshy: PORTULACACEAE | |
| | 76. | Plant not fleshy | 🠚 77. |
| | | | |
| 🠘 | 77. | Sepals early-caducous; leaves lobed: PAPAVERACEAE | |
| | 77. | Sepals not early-caducous; leaves dissected: FUMARIACEAE | |
| | | | |
| 🠘 | 78. | Flowers regular; all petals similar | 🠚 79. |
| | 78. | Flowers markedly irregular; petals not all similar | 🠚 81. |
| | | | |
| 🠘 | 79. | Sepals and petals 4; stamens 6, 2 shorter than the others: CRUCIFERAE | |
| | 79. | Sepals 5; stamens 5, 8, or 10, all the same length | 🠚 80. |
| | | | |
| 🠘 | 80. | Ovary 5-lobed with long beak bearing 5 stigmas; flowers solitary on long peduncles; leaves lobed or dissected: GERANIACEAE | |
| | 80. | Fruit a many-seeded capsule; leaves entire: PYROLACEAE | |
| | | | |
| 🠘 | 81. | Flowers papilionaceous (as in the pea), with stamens forming
tube around style; fruit a legume; leaves compound: LEGUMINOSAE | |
| | 81. | Flowers not papilionaceous; fruit a 1-roomed, 3-valved capsule;
leaves entire | 🠚 82. |
| | | | |
| 🠘 | 82. | Sepals 3, very unequal, 1 spurred; petals 3, not spurred; stipules lacking; flowers panicled: BALSAMINACEAE | |
| | 82. | Sepals 5, equal, not spurred; petals 5, 1 spurred; stipules pres-
ent; flowers solitary: VIOLACEAE | |
| | | | |
| 🠘 | 83. | Ovary superior | 🠚 84. |
| | 83. | Ovary inferior, or partly so | 🠚 103. |
| | | | |
| 🠘 | 84. | Stamens more than 5 | 🠚 85. |
| | 84. | Stamens not more than 5 | 🠚 89. |
| | | | |
| 🠘 | 85. | Petals united only near base | 🠚 86. |
| | 85. | Petals markedly united, often urn-shaped or tubular; style 1 | 🠚 88. |
| | | | |
| 🠘 | 86. | Corolla irregular; pistil 1; stamens 6: FUMARIACEAE | |
| | 86. | Corolla regular | 🠚 87. |
| | | | |
| 🠘 | 87. | Pistils 5; stamens 10; plant succulent: CRASSULACEAE | |
| | 87. | Pistil 1; stamens 8-12, mostly 10: PYROLACEAE | |
| | | | |
| 🠘 | 88. | Plant an evergreen herb, or saprophytic herb, lacking
chlorophyll; anthers opening by longitudinal slits: PYROLACEAE | |
| | 88. | Plant a shrub or dwarf shrub; anthers opening by an apical pore:
ERICACEAE | |
| | | | |
| 🠘 | 89. | Plant lacking chlorophyll, brown, parasitic; corollas with 3-lobed lower lip; stamens 4: OROBANCHACEAE | |
| | 89. | Plant with chlorophyll, not parasitic, or partly so | 🠚 90. |
| | | | |
| 🠘 | 90. | Corolla regular | 🠚 91. |
| | 90. | Corolla irregular | 🠚 101. |
| | | | |
| 🠘 | 91. | Pistils 2 (ovaries distinct, but styles united) ; plant with
milky juice: APOCYNACEAE | |
| | 91. | Pistil 1 | 🠚 92. |
| | | | |
| 🠘 | 92. | Stamens as many as corolla lobes and opposite them | 🠚 93. |
| | 92. | Stamens as many as, or fewer than, corolla lobes and alternating with them
| 🠚 94. |
| | | | |
| 🠘 | 93. | Style 1; fruit a several-seeded capsule: PRIMULACEAE | |
| | 93. | Styles 5; fruit 1-seeded; leaves linear: PLUMBAGINACEAE | |
| | | | |
| 🠘 | 94. | Corolla small, dry-scarious, veinless; capsule opening with a lid; stamens
2 ot 4;leaves basal: PLANTAGINACEAE | |
| | 94. | Corolla not dry-scarious, veiny; capsule not opening with a lid; stamens 5
| 🠚 95. |
| | | | |
| 🠘 | 95. | Ovary with 4 rooms, usually 4-lobed (though some may abort); plant
characteristically scabrid, hispid; inflorescence usually a scorpioid
cyme: BORAGINACEAE | |
| | 95. | Ovary with 1, 2, or 3 rooms | 🠚 96. |
| | | | |
| 🠘 | 96. | Anthers opening with apical pores; flowers large, red: ERICACEAE (Rhododendron) | |
| | 96. | Anthers opening with longitudinal slits | 🠚 97. |
| | | | |
| 🠘 | 97. | Style 3-cleft; ovary 3-roomed; capsule 3-valved | 🠚 98. |
| | 97. | Style not 3-cleft; ovary 1-2-roomed | 🠚 99. |
| | | | |
| 🠘 | 98. | Plant an evergreen, dwarf shrub with entire, leathery leaves; filaments in notches of corolla, cohering with corolla; flowers solitary: DIAPENSIACEAE | |
| | 98. | Plant an herb with entire or often pinnately divided leaves;
filaments not in notches of corolla: POLEMONIACEAE | |
| | | | |
| 🠘 | 99. | Calyx deeply 5-lobed; style often 2-cleft: HYDROPHYLLACEAE | |
| | 99. | Calyx 4-5-toothed or cleft; style 1, entire | 🠚 100. |
| | | | |
| 🠘 | 100. | Stigmas 2; ovary 1-roomed: GENTIANACEAE | |
| | 100. | Stigma 1; ovary 2-roomed: SOLANACEAE | |
| | | | |
| 🠘 | 101. | Ovary 4-lobed; style arising between ovary lobes, cleft at apex: LABIATAE | |
| | 101. | Fruit a capsule | 🠚 102. |
| | | | |
| 🠘 | 102. | Ovary 2-roomed: SCROPHULARIACEAE | |
| | 102. | Ovary 1-roomed: LENTIBULARIACEAE | |
| | | | |
| 🠘 | 103. | Leaves ternately compound; flowers in cube-like head: ADOXACEAE | |
| | 103. | Leaves not ternately compound | 🠚 104. |
| | | | |
| 🠘 | 104. | Stamens more than 5: ERICACEAE | |
| | 104. | Stamens 5 or fewer | 🠚 105. |
| | | | |
| 🠘 | 105. | Stamens distinct | 🠚 106. |
| | 105. | Stamens adnate to corolla, their anthers united to a tube;
flower in involucrate heads; fruit an achene, often with plumose
pappus: COMPOSITAE | |
| | | | |
| 🠘 | 106. | Leaves alternate; flowers regular; stamens 5: CAMPANULACEAE | |
| | 106. | Leaves opposite or whorled | 🠚 107. |
| | | | |
| 🠘 | 107. | Stamens 1-3; flowers irregular; fruit 1-seeded: VALERIANACEAE | |
| | 107. | Stamens 4-5; flowers mostly regular, sometimes irregular | 🠚 108. |
| | | | |
| 🠘 | 108. | Plant an herb; ovary 2-roomed; leaves whorled: RUBIACEAE | |
| | 108. | Plant a shrub or rarely an herb (Linnaea); ovary mostly 3-5-roomed;
leaves opposite; flowers regular or irregular: CAPRIFOLIACEAE | |
| | | | |